Stanchions and Dissimilar Metals

[jac]

I have recently purchased a Dufour 36 Classic and one of the winter jobs is to to add gates in the guardrail to allow easier access.

The 36 classics have aluminium stanchion bases bolted through the aluminium toe rail and then stainless stanchions and guardrails. The topic of basic chemistry and dissimilar metals has been raised a couple of times in various threads in owner forums!

Predictably the original stanchion bases are no longer made so matching is irrelevant.

My options are to either go with something like this Aluminium Toe Rail Stanchion Base | YS Fittings | Proboat and then my choice of gate stanchion in stainless ( relying on the PTFE sleeve for protection, or to buy a stainless base and rely on duralac or similar to protect it / the toerail.

Has anyone done anything similar? ANy thoughts on the durability of a PTFE sleeve over that of duralac? or the durability of bolts??

 

[PetiteFleur]

The YS stanchion bases you mention are fitted to my Moody 33 when I bought it years ago. Originally made without the ptfe sleeve but now fitted. I had aluminium stanchions secured with a stainless bolt ... I had to renew most of them as the stainless wire had worn through the aluminium stanchion. One snapped one winter so I renewed both bases and stanchions. I was lucky and got 'shop soiled' bases and stanchions from ebay at a knockdown price. Note that the bases are also bolted through the deck as well as the toe rail.
Very expensive now but if you're quick, 2 on ebay at the moment at £69.99 each + £3.85 postage.
edit I've had no problems with ptfe sleeve and better than Duralac.

 

[PetiteFleur]

Also cheaper than the list price at Chas Newens Marine.

 

[geem]

I have recently purchased a Dufour 36 Classic and one of the winter jobs is to to add gates in the guardrail to allow easier access.

The 36 classics have aluminium stanchion bases bolted through the aluminium toe rail and then stainless stanchions and guardrails. The topic of basic chemistry and dissimilar metals has been raised a couple of times in various threads in owner forums!

Predictably the original stanchion bases are no longer made so matching is irrelevant.

My options are to either go with something like this Aluminium Toe Rail Stanchion Base | YS Fittings | Proboat and then my choice of gate stanchion in stainless ( relying on the PTFE sleeve for protection, or to buy a stainless base and rely on duralac or similar to protect it / the toerail.

Has anyone done anything similar? ANy thoughts on the durability of a PTFE sleeve over that of duralac? or the durability of bolts??

Why not use aluminium stanchions in aluminium stanchion bases

 

[jac]

Also cheaper than the list price at Chas Newens Marine.

Thanks for that - yes I think they are cheapest there. I think the model may have changed design - the spec sheet clearly says 2 fixing holes and the diagram shows position for 2 M6 bolts that go through the toe rail

 

[jac]

Why not use aluminium stanchions in aluminium stanchion bases

Was worried about the durability of aluminium stanchions with a guardrail through them to be honest - not so much galvanic corrosion but the saw effect of the guardrail on the hole in the stanchion and also gate stanchions seem to all be 316 stainless. I could get some Alu ones made i guess but that feels like it's getting out of hand!

I also see that PetitFleur had the issue of the stanchions themselves being destroyed by the guardrail.

 

[geem]

Was worried about the durability of aluminium stanchions with a guardrail through them to be honest - not so much galvanic corrosion but the saw effect of the guardrail on the hole in the stanchion and also gate stanchions seem to all be 316 stainless. I could get some Alu ones made i guess but that feels like it's getting out of hand!

I also see that PetitFleur had the issue of the stanchions themselves being destroyed by the guardrail.

In 2020 we refitted out boat. We replaced the aluminium toerail and aluminium stanchions. At that point, everything was 40 years old. The solid aluminium stanchion are far stronger than stainless steel tube stanchions. The new toerail also has new aluminium stanchions. Why change to something inferior. We see our guardrails as a primary safety device.

 

[Laysula]

Sleeve the stanchion with a bit of pneumatic air hose. It protects the aluminium stanchion from the stainless wire and (Particularly if it's plastic coated) the stainless wire from the stainless stanchion.

 

[Birdseye]

I have recently purchased a Dufour 36 Classic and one of the winter jobs is to to add gates in the guardrail to allow easier access.

The 36 classics have aluminium stanchion bases bolted through the aluminium toe rail and then stainless stanchions and guardrails. The topic of basic chemistry and dissimilar metals has been raised a couple of times in various threads in owner forums!

Predictably the original stanchion bases are no longer made so matching is irrelevant.

My options are to either go with something like this Aluminium Toe Rail Stanchion Base | YS Fittings | Proboat and then my choice of gate stanchion in stainless ( relying on the PTFE sleeve for protection, or to buy a stainless base and rely on duralac or similar to protect it / the toerail.

Has anyone done anything similar? ANy thoughts on the durability of a PTFE sleeve over that of duralac? or the durability of bolts??

I used a sleeve cut out of a yoghurt pot or similar. PTFE tape is fragile and stanchions move.

 

[jac]

I used a sleeve cut out of a yoghurt pot or similar. PTFE tape is fragile and stanchions move.

Looking at the spec sheet it looks like a tube of PTFE rather than tape

 

[PetiteFleur]

Yes, I did sleeve the stanchions with a short length of nylon tubing secured at one end with self amalgamating tape. I did ask the wire supplier to add the tubing before he made up the wire but he forgot so I fitted a short length spiral cut to get it on the wire.